Pure water treatment equipment is necessary in water treatment processes used in power plants and electronic industrial plants. In traditional industrial pure water treatment technologies, Electrodialysis and ion exchange technologies are combined to develop products and methods for getting ultra pure water. For example, Chinese Patent No. 96244875.4 shows one type of treatment equipment. Resins are filled in normal electrodialysis dilute chamber and Anode and Cathode electrodes are placed outside the module. The advantage of this approach is that it has the same distance between every two membranes and reliably stable resistivity so that the current intensity is relatively easy to control. The disadvantage of this approach is that it is difficult to fill the chambers with resin. In fact, special ion fiber knitting is used to help alleviate the problem.
To further resolve this disadvantage, some EDI modules are formed having a wound cylinder structure. Chinese Patent No. 00220610.2 entitled “Polyhedron Wound EDI” shows this kind of treatment equipment. In the polyhedron wound EDI, Anionic/Cationic membranes/isolation support frames form a special dilute chamber and concentrate envelop chamber which connect to the dilute/concentrate collecting pipes. The dilute envelope chamber is filled with resins, and Anode/Cathode electrodes are set up. The improvement of Chinese Patent No. 00220610.2 is that the ion membranes/support frames are polyhedron. The dilute water comes from multi-connected rectangle chambers. This patent partly resolves some issues of resin filling for resins not limited in ion fiber knitting. However, the support frame has its disadvantages. Water can not flow easily in the dilute chamber, so resins cannot be conveniently filled.
U.S. Pat. No. 6,190,528, issued Feb. 20, 2001 to Xiang Li et al. discloses a helical EDI apparatus. However, the Xiang Li patent does not disclose a dilute support frame. U.S. Pat. No. 6,190,528 is incorporated by reference herein in its entirety.